Manufacture of chromable secondary disazo dyestuffs.



UNITED 'sirairas Pair MELCHIOB BOENIGER, OF BASEL, SWITZERLAND, ASSIGNOR'IO CHEMICAL WORKS FORMERLY SANDOZ, OF BASEL, SWITZERLAND.

MANUFACTURE OF CHROMABLE SECONDARY DIS AZO DYESTUFES.

No Drawing.

To all whom it may concern Be it known that I, MnLci-uon BOENlGER,

. of Basel, Switzerland, a citizen of the Swiss Republic, have inventedcertain new and useful Improvements 1n the Manufacture of (PhromableSecondary Disazo Dyestuffs, of

\ fonic acid, new and very valuable o-oxydisazo dyestuffs are formed,whose dyeings on wool are changed by subsequent chroi ing into brown tobronze-brown shades fast to milling and potting and of excellent fast--ness to light. I

- Example 1: The monoazo dye obtained from 19.9 parts diazotizedpicramic acid and 23.9 parts 2-amino8-oxynaphthalene-6- sulfonic acid byalkaline combination, is diazotized with 7 parts of nitrite, and thediazo compound is coupled with the soda alkaline solution of 25.4- partsof l-p-sulfophenyl-3-1nethyl-5-pyrazolone The dyestufl is precipitatedby addition of common salt, filtered off and dried. In an acid bath itdyes unmordanted wool in red brown shades, changing on subsequentchroming into bronze brown fast to milling and potting and of excellentfastness to light.

Example 2: Diazotize the monoazo dye obtained in alkaline solution from23.4 parts of diazotized 2-amino-6-nitr0-l-oxybenzoll-sulfonic acid and23.9 parts of 2amino-8 oxynaphthalene-6-sulfonic acid with 7 parts ofnitrite, and combine with the soda alkaline solution of 17.4 parts of1-phenyl-3- methyl-5-pyrazolone. The disazo dyestuif separates outimmediately in the form of a" black powder, which is worked up as usual.It produces on wool in an acid bath reddish brown shades, turning tobronze brown on subsequent chroming. The after chromed dyeings aredistinguished by an excellent fastness to washing, milling and light.

Specification of Letters Patent.

Application filed May 13, 1916.

Patented Sept. 26, 1916. Serial No. 97,294.

What I claim and ters Patent is:-

1. Process for the manufacture of chromable secondary disazo dyestuffs,comprising further diazotizing the monoazo dyestufi' obtained inalkaline combination. from an o-diazo 'iheno'l and2-amino-S-oxynaphthalene-(i-sulfonic acid, and coupling the resultingbody with a pyrazolone having its 4 position unoccupied.

Process for the manufacture of chromable secondary disazo dyestuffs,comprising further diazotizing the monoazo dyestulf obtained in alkalinecombination from a nitro-odiazophenol and2-amino-8-oxynaphthalene-6sulfonic acid, and coupling the resulting bodywith a pyrazolone having its l gosition unoccupied.

8. recess for the manufacture of chromable secondary disazo dyestuffs,comprising further diazotizing the monoazo dyestufi' obtained inalkaline combination from 2-di-- azo-6-nitro-l-oxybenzoli-sulfonie acidand Q-amino-S-oxynaphthalene-6-sulfonic acid, and coupling the resultingbody with a pyrazolone having its 4- position unoccupied.

4. Process for the manufacture of chromable secondary disazo dyestulfs,comprising further diazotizing the monoazo dyestuff obtained in alkalinecombination from 2- diazo-6-nitro-1 oxybenzol l 4 sulfonic acid and2-amino-8 oxynaphthalene 6 sulfonic acid, andcoupling the resulting bodywith l-p-sulfophenyl-3-methyl-o-pyrazolone.

The new secondary o-oxydisazo dyestuffs being derived from pyrazolonesof unoccupied 4 position and a. diazotized' desire to secure by Let-'milling, potting" and flight, yielding .upon reduction with stannouschlorid and hydrochloric acid an amino o-aminophenol compound,2.7-diamino-S-Oxynaphthalene-G-sulfonic acid and a -amino-fi-pyrazolonecompound.

v 7. The new secondary o-oxydisazo dyestuffs being derived frompyrazolones of unoccupied 4 position and a diazotized monoazo dyestufl',obtained'by alkallne combination of2-diazo-6-nitr0-1-oXybenzo1-4lsulfonic. acid WithQ-amino-S-oxynaphthalen-6-sulfonic acid, giving by subsequent chromingof their dyeings on Wool, brown shades fast to milling, potting andlight, yielding upon reduction with stannous cl1lorid and hydrochloricacid 2.6-diamino-1- oxybenzol-l-sulfonic acid and a-4-amino-5-pyrazolone compound.

8. The new secondary o-oxydisazo dyestiifi being derived froml-fi-sulfophenyl-iimethyl-fi-pyrazolone and a diazotized monoazodyestuff obtained by alkaline combination of Q-diazo-(i-nitro-loxybenzol4 sulfonic acid with 2-amino-8-oxynaphthalene; 6-sulfonic acid, givingby subsequent chroming of. its dyein gs on WOO shades fast to milling,potting and light, yielding upon reduction with rid and hydrochloricacid 2.6-diamino-l-cxybenzol-i-sulfonic acid and 1-p-sulfophenyl-3-methyl-4-amino-5pyrazolone.

In Witness whereof, Iv have hereunto signed my name in the presence oftwo subscribing Witnesses.

MELCHIOR BOENIGER.

\Vitnesses v GEO. H. 'WVAGNER, v lVERNER PAUFFAEBERY.

. Copies 0! this patent may be obtained for five cents each, 0addressing-the Commissioner of l'ata'nts,

Washingtom-D. C.

stannous chlo-' bronze brown

